1. Field of the Invention
The present invention relates to a semiconductor device formed by bonding a semiconductor thin film such as an LED epitaxial film to a substrate, to an LED print head using this semiconductor device, to an image-forming apparatus using this LED print head, and to a method of manufacturing the semiconductor device.
2. Description of the Related Art
In the conventional art, the electrical connection between an LED chip and a driver IC chip for driving and controlling the LED chip, was made by a bonding wire (e.g., Japanese Patent Laid-Open Publication No. 2001-244543). FIG. 13 is a perspective view schematically showing a conventional semiconductor device wherein an LED chip and a driver IC chip are connected by bonding wires, and FIG. 14 is a perspective view showing an enlargement of the LED chip of FIG. 13. As shown in FIG. 13 or FIG. 14, the semiconductor device includes a unit board 301, an LED chip 302, and a driver IC chip 303. The LED chip 302 includes light-emitting parts 304, discrete electrodes 305, and electrode pads 306. The electrode pads 306 of the LED chip 302 and the electrode pads 307 of the bonding IC chip 303 are connected by bonding wires 308. Further, electrode pads 309 of the driver IC chip 303 and electrode pads 310 of the unit board 301 are connected by bonding wires 311.
However, in the aforesaid conventional semiconductor device, a surface area of electrode pads 306 (e.g., of the order of 100 μm×100 μm) is larger than the surface area occupied by the light-emitting parts 304 on the LED chip 302. Therefore, as long as the electrode pads 306 are provided, it is difficult to reduce the chip width of the LED chip 302, and difficult to reduce the material cost of the LED chip 302.